1. Field of the Invention
The invention relates to a field effect transistor driver circuit.
2. Description of the Prior Art
In general, it is the object of such driver circuits to supply at a predetermined moment, without considerable power dissipation of its own, a relatively high output current which is required at the output for driving a load capacitance which is large compared with the input capacitance.
Particularly in highly integrated digital circuits there is a problem of generating, out of one single externally applied clock pulse, a series of further (internal) pulses whose succession with respect to time is predetermined by the operation of the overall circuit. The requirements of such a single driver circuit generally consist of providing a pulse of a predetermined form which, relative to the predetermined input pulse, is delayed by a defined time and which also shows a short rise and/or fall time. Contrary to the input pulse source, a high current driving capacity is required of the output pulse, i.e., it has to be loadable with a high capacitance which in monolithically integrated semiconductor circuits, particularly FET circuits, is formed by the inputs of subsequent circuits to be driven and their interconnecting lines.
Driver circuits with field effect transistors are known in a multitude of designs already. The following literature references can be considered to be representative for prior art in this field: U.S. Pat. Nos. 3,631,267; 3,769,528, 3,898,479 and 4,061,933, as well as the publications in the IBM Technical Disclosure Bulletin, Vol. 16, No. 1, June 1973, pages 50/51; Vol. 17, No. 10, March 1975, page 2834; Vol. 18, No. 4, September 1975, pages 1028/1029 and Vol. 19, No. 1, June 1976, pages 31/32.
The circuit of FIG. 1 can be considered the typical prior art for the fundamental structure of a driver circuit which is the basis for the invention to be described below. The fundamental circuit structure shown there which consists of several partial circuits is known, e.g., from U.S. Pat. No. 4,122,361 with further references.